Lifting-jack.



PATENTED OCT. 8, 1907.

G. R. BOOTH. LIFTING JACK.

urmouron rmm JULY 5. 1907.

INVENTOR 6762223300670 WITNESSES WWW/m A TTOHNEYS' A W m u m y I m-UVITED STATES GLEN RUSSELL BOOTH, OF GHANA, ILLINOIS.

LIFTIIi'G-J'ACK.

Specification of Letters Patent.

Patented Oct. 8, 1907.

Application filed July 5, 1907. Serial No. 382,378.

To all whom it may concern:

Be it known that I, GLEN RUSSELL BOOTH, a citizen of the United States,and a resident of Ghana, in the county of Ogle and State of Illinois,have invented new and useful Improvements in Lifting-Jacks, of which thefollowing is a full, clear, and exact description.

This invention is an improvement in lifting jacks, the purpose of whichis the provision of a comparatively simple and practical jack, embodyinga construction consisting of a base carrying a slotted standard in whichis slidably mounted a lifting bar, the said bar having an adjustableload-supporting member on one side and an operating lever, the latterbeing pivotally and slidably supported in inclined slots formed in theslotted standard and operating to automatically disengage and rengagethe teeth of the lifting-bar as the lever is reciprocated. Thelifting-bar is automatically engaged and held during the lifting of theload by a springpressed pawl, which is provided with a projection on itsinner face adapted to be thrown into engagement with the said teeth bythe operating lever, which action disengages the pawl proper from theteeth of the lifting-bar and serves as a brake in lowering the load. Thepawl is also constructed with projecting fingers at opposite sides fordisengaging it from the lifting-bar by hand.

Reference is to be had to the accompanying drawings forming a part ofthis specification, in which similar characters of reference indicatecorresponding parts in all the views.

Figure 1 is a side elevation of my improved jack complete; Fig. 2 is acentral vertical section of the same; Fig. 3 is a plan of the jack; andFig. 4 is a sectional view similar to Fig. 2 on an enlarged scale.

More specifically stated, the construction of the jack comprises a base10 of suitable extent, which supports a standard or frame 11., thelatter being slotted substantially its entire length for receiving aslidable liftingbar 12. The connection between the standard and base isstrengthened by the radiating flanges or ribs 13, and the standard isstrengthened internally by parallel cleats 11, and externally byparallel cleats 11", as shown in Figs. 1 and 2.

As best shown in Fig. 3, the lifting-bar is of reduced thickness on itslongitudinal center, which provides it with thickened heads at oppositesides, the edges of the inner head being (love-tailed adjacent to thereduced central portion of the bar, as indicated at 14, which providesfor the snug but free sliding engagement with the standard 11.

The outer head of the lifting-bar is provided on its front face withrack-teeth 15 which are engaged by a load-supporting member or block 16,said block having .a tooth 17 at its lower end for this purpose, andconstructed with straps 18 at its top which embrace the head of the bar12 at opposite sides, as clearly shown in Fig. 3. This constructionadapts the block to be ad justed longitudinally of the lifting-bar andengaged with any of the rack-teeth by tilting it slightly upward todisengage the tooth 17. In this way the block 16 may be moved directlyinto contact with the load to be lifted without the necessity ofelevating or depressing the lifting-bar for this purpose. I

On the inner face or head of the lifting-bar 12 are formed rack-teeth 19which are adapted to be engaged by the teeth of a segmental gear 20formed on the inner end of an operating lever 21, the said lever beingpivotally and slidably supported on the projecting ends of a pivot pin22 which are in engagement with the downwardly and inwardly inclinedslots 23, the said slots being formed in the sides of the standard 11and arranged on a slight are as shown. Also in normal engagement withthe rack-teeth 19 of the lifting-bar is a pawl 24 which is preferablypivotally supported in the slotted standard 11 above the lever, and ispressed in the direc tion of the lifting-bar by a spring 25, the latterbeing engaged with a projection on the rear face of the pawl and seatedwithin a. recess formed in a lug 26, which connects the upper ends ofthe two portions of the standard 11, as clearly shown in Fig. 2.

The pawl 24 is constructed with a depending tail 27 which isprovided onits inner face with a projection of tooth 28 beveled at the top, asshown, and adapted when the pawl is thrown from engagement with thelifting-bar to itself engage the teeth and provide a brake when the loadis lowered. This is accomplished automatically by throwing the operatinglever 21 to the dotted position shown in Fig. 2, which brings aprojection or lug 29 formed on the lever into engagement with theenlarged extremity 30 of the pawl, forcing the same to the dottedposition indicated. The pawl may also be disengaged from the teeth ofthe rackbar by hand, for which purpose fingers 31 project from theopposite sides thereof through slots 32 formed in the standard 11.

Over the slots 23 are arranged cap plates 33, as shown in Figs. 1 and 3,and which serve as coverings to protect the gear 20 and preventinterference therewith during the. effective working of the operatinglever 21. The engagement of the beveled or dove-tailed edges of thelifting-bar 12 with the opposing edges of the standard 11, lessens thespreading pressure on the standard, strengthens the jack as a whole, andalso produces a binding or braking effect at that point. When pres sureis put upon the operating lever 2l,forcing the brake tooth 28 againstthe teeth of the lifting bar 12, the latter is forced directly againstthe dove-tailed parts.

In operating the jack, the load is ordinarily brought to bear directlyon the supporting block or member 16, or it may rest directly on the topof the lifting-bar, which, as shown, is scalloped out as indicated at 33to prevent slipping and also to fit under the axle of a wagon, carriage,automobile or other vehicle, thus avoiding any scratching of the same.On reciprocating the lever 21, its toothed inner end automaticallyslides upwardly in the slots 23 as the handle 21 is raised, and carriessaid teeth out of the path of the rack-teeth 19. On, however, depressingthe lever the toothed sector drops to the bottom of the slots 23 andengages the rack-teeth, causing the lifting-bar to move upwardly, thesame being automatically engaged and held when the lever is beingelevated by the pawl 24. If it is desired to drop the load suddenly, theoperating lever is carried upward to the dotted line position shown atthe top of Fig. 2, and the jack is suddenly released, just enoughpressure being applied to the lever 21 to release the pawl 24. When itis desired to apply the brake, the operating lever 21 is forced inwardlywith consideiable pressure and the tooth 28 carried by the tail 27 ofthe pawl 24, is forced into contact with the teeth 19-, thus breakingthe fall of the jack. The jack may be released slowly by hand and underperfect control, by simply allowing the operating lever to drop downwardengaging its teeth with those on the lifting-bar'and then, on applyingsufiicient pressure on the operating lever to raise the lilting-bar inorder to remove the pressure from the pawl, the pawl may be released andheld out of contact by the fingers, while the lever is allowed to rise,and at the same time the lifting-bar is lowered very carefully and underfull control of said lever. The lifting-bar may be lowered to anydesired distance by repeating the above operation.

The invention as shown and described while being the. preferredpractical construction of the jack, may he obviously modified innumerous minor particulars within the scope of the invention as definedin the annexed claims.

Having thus described my invention, 1 claim as new and desire to secureby Letters Patent:

1. In a lifting jack. a slotted standard, a lifting-bar slidziblymounted within the slot 01' said standard having hack-teeth formed atone side thereof. said lifting-bar being reduced in thickness on itslongitudinal center. forming thickened heads at opposite sides. theedges of the inner head being. dove-tailed adjacent to the reducedcentral portion of said lifting-bur, an operating lever hav' ing atoothed inner end adapted to engage the teeth of the lifting-bar andpivotally supported in inclined slots formed in the standard, and a pawlpivoted to said standard adapted to automatically engage the teeth ofthe liftingbar and support the same as the bar is elevated.

" In a lifting jack, a slotted standard, a lifting-bar slidably mountedin the slot of said standard, having rackteeth at one side thereof. anoperating lever having a l I l l toothed inner end adapted to engage theteeth of said lifting-bar, and a pawl engaging the teeth of said bar,hav ing 21 depending tail provided with -a brakingtooth adapted to bethrown into engagement with the teeth of the lifting-bar by theoperating lever.

23. In a lifting jack, a base supporting a slotted standard, alifting-bar slidably mounted in the slot of said standard, havingrack-teeth formed at one side thereof, said lifting-bar being scallopedout at its upper end, an operating lever having a toothed inner endpivotally and slidably supported in inclined slots formed in saidstandard and adapted to engage the teeth of the lifting bar, and a pawlnormally engaged with the teeth of said bar, having a depending tailprovided with a braking-tooth or projection on its inner face adapted tobe thrown into engagement with the teeth of the lifting-bar by theoperating lever.

4. In a lifting jack, a lifting-bar having rack-teeth, an operatinglever having a toothed inner end adapted to engage the teeth of therack-bar, a pawl adapted to automatically engage the teeth of thelifting-bar and support the same as the bar is elevated by the operatinglever, said pawl having 9. depending tail provided with a brakingtoothadapted to be thrown into engagement with the teeth of the lifting-barfor the purpose described.

5. In a liftingjack, a slotted standard, a lifting-bar slidably mountedwithin the slot of said standard, having rack-teeth formed at one sidethereof, an operating lever having a toothed inner end adapted to engagethe teeth of the lifting-bar, a pawl normally engaged with the teeth ofsaid bar, having 9. depending tail provided with a braking-tooth adaptedto be thrown into engagement with the teeth of the liftingbar by theoperating lever, and fingers projecting from the opposite sides of saidpawl through slots formed in said standard for the purpose described.

6. In a lifting jack, :1 standard, a lifting-bar slidably mounted on thestandard, having rack-teeth formed at one side thereof, an operatinglever having a toothed inner end adapted to engage the teeth of thelifting-bar, a spring pressed pawl normally engaged with the teeth ofthe lifting-bar, having a depending tail provided with a brakingtooth,and :1 lug formed on the operating lever adapted to engage the said tailof the pawl and force said brakingtooth into engagement with the teethof the lifting-bar for the purpose described.

7. In a lifting jack, :1 standard, a lifting bar slidably mounted on thestandard, having rack teeth formed at one side thereof, said lifting barbeing reduced in thickness on its longitudinal center, forming thickenedheads at opposite sides, the edges of the inner head being dove tailedadjacent to the reduced central portion of said lifting-bar, anoperating lever having a toothed inner end adapted to engage the teethof the lifting-bar, a springpressed pawl normally engaged with the teethof the lifting bar, having a depending tail provided with a brakingtooth, and a lug formed on the operating lever adapted to engage thesaid tail of the pawl and force said braking tooth into engagement withthe teeth of the lifting-bar for the purpose described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

GLEN RUSSELL BOOTH.

Witnesses W. Wns'r.

